The present invention relates generally to digital electronic timepieces whose displayed time can be readily corrected (hereinafter referred to as "time adjusted"), and more particularly to a digital electronic timepiece (hereinafter referred to as a digital electronic clock) which, when its displayed time is within a specific "minute" range, can be time corrected with the "hour" display within this "minute" range and, moreover, in such a manner that the "minute" and "second" displays become zero.
The method of time correcting or adjusting a conventional digital electronic clock has comprised, in the case where the displayed time is retarded (slow) relative to the correct time, carrying out fast-forward running to set the display at an advanced time relative to the correct time, temporarily stopping the clock once in this state, and subsequently restarting the clock when the displayed time and the time heard over standard time signal means, such as the telephone, coincide. Another conventional time adjusting method has comprised carrying out fast-forward running and setting the display time at n hr. 00 min. 00 sec., temporarily stopping the clock once in this state, and then restarting the clock when the displayed time and a time signal heard over the television, radio, telephone, or the like coincide.
For carrying out these operations in the time adjusting of a conventional digital electronic clock, it has been disadvantageously necessary to carry out complicated manipulations of switch buttons to place the display in the fast-forward running mode, thereafter to place it in the stop mode, and subsequently to place it in the start mode.
Furthermore, in known electronic wristwatches, in the case when the second display is within a specific second range, there has been a method wherein only the second display is time adjusted as m min. 00 sec. In general, however, in a digital electronic clock in an installation such as that in a motor vehicle, there are cases wherein, because the electrical power source is temporarily cut off at the time of servicing, noise from the outside is caused by occurrences such as sparking, whereby the displayed time becomes greatly incorrect. Consequently, even when the clocking circuit, per se, operates accurately and positively, since the displayed time deviates greatly on the basis of special characteristics due to the installation such as that in a motor vehicle as mentioned above, the time adjustment circuit of a wristwatch, in which circuit time adjustment is carried out with second units, is not applicable.